PERCOMOEPHI, 97 



caudal fin) 2.60 times. Mouth rather small ; length of head entering total 

 length 3.8 times. Short conic teeth en brosse. Preorbital and preopercular 

 bones finely serrated on their free margins. Vertebrae: D. 7; C. 14. Radii: 

 D. X — 14; A. Ill — 11; V. I. 5 or 6. The dorsal spines are rather slender; 

 the anal spines are stouter, but shorter; the ventral spine is weak and 

 slender. The ventral fin when appressed against the belly fails to reach 

 the anal fin by a space a little greater than the length of the ventral spine; 

 its origin is beneath the third dorsal spine. The scales are difficult to 

 observe on the specimens, but there are not less than fifteen to seventeen 

 longitudinal rows along the abdomen in front of the anal fin. 



Measurements. m. 



Total length 130 



Axial length of head 035 



Axial length to first dorsal spioe 038 



Axial length to first dorsal soft ray 062 



Axial length to first anal spine 070 



Axial length to base of caudal fin 103 



Depth at orbit 025 



Depth at first anal spine 041 



Depth of caudal peduncle 016 



Length of fifth dorsal spine 019 



This species is similar in size and proportions to the Priscacara Hops, 

 but difi"ers in having constantly but seven dorsal or abdominal vertebrae, 

 while that species presents nine. I have not observed any serratures on the 

 preoperculum of the P. Hops, but the typical specimens are imperfect in that 

 region, although good impressions of it remain on the matrix. 



Two complete specimens present all the characters of this species, 

 while in two others all the more important ones can be seen. Two addi- 

 tional specimens may be referred to it with the greatest probability, and I 

 have found it abundant in various collections. Some were obtained by Dr. 

 A. C. Peale, in charge of one of the parties under Dr. F. V. Hayden, from 

 the shales of the Green River formation of Wyoming. The species is dedi- 

 cated to Dr. Peale, in recognition of his services to geological science. 



Pkiscacara liops Cope. 



Bulletin U. S. Geol. Surv. Terrs., 1877, p. 818. 

 Plate XIV, figs. 2-3. 



A smaller fish than either of the preceding is referred to this genus, 

 although it differs in one feature, regarded as important among the Poma- 

 7 o 



